Alloy



Patented May 17, 1927.

UNITED srATEs PATENT OFFICE.

FRANCIS F. LUCAS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ALLOY.

No Drawing.

This invention relates to alloy steels and it has an object-to provide a" high quality' brittle or tough characteristics so as to make it suitable for use in the form of tape or heavy wire. Further,-it is preferable that satisfactory cable armor materials are substantially non-magnetic, non-corrodible or oxidizable and are especially resistant to abrasion. Many materials which are satisfactorily resistant to abrasion possess a structure which is substantially too brittle for application in the form of a wire or tape. Similarly, other materials which are satisfactorily non-magnetic and which are sufiiciently tough and ductile do not possess sufficient resistance to abrasion for use as armoring for cables. Many alloy steels have been found to be abrasion resistant and non-magnetic but not tough or ductile; others which are sufliciently tough and duetile are unsatisfactorily non-magnetic.

In accordance with the features of this invention, there is provided a group of al- 10y steels suitable for cable armoring comprising steel alloys containing nickel, tungsten, chromium and manganese as special alloying elements. It has been found that alloys composed of the above noted metals in accordance with the invention possess resistance to abrasion, the non-magnetic quality, are not corrodible and when annealed, will become tough and non-brittle without being affected as regards their other qualities, so that they make exceedingly good materials for use as cable armors, for example.

The proportions of special alloying metals which have been employed in forming these steel alloys may be considerably varied, changes 1n such proportions, of course, varying the toughness, hardness, magnetic quality, and resistance to abrasion of the Application filed October 3, 1925. Serial No. 61,163.

particular alloy formed. It is preferable in any nstance to choose the proportions of the special alloying elements so that the steel formed is non-magnetic.

In general, it has been found that each of the yarious outstanding properties of the particular alloy formed may be directly traced to certain of the special alloying elements employed, and the degree in which any one property is possessed by the alloy depends substantially upon the pro 'aortion of the special alloying element or elements to which that property is due. In choosing theproportions of the various special alloying elements to be employing in any given case, the relation between all the elements in the alloy formed is preferably made such as to promote the formation of an austenitic isteel to insure the absence of magnetic qualiies.

It has been found desirable to incorporate nickel in the alloy, since nickel has been found to impart toughness and promote the tendency ofthe steel to become austenitic at atmospheric temperatures. In accordance with these results the nickel content is preferably maintained between 7 and 20%.

The non-corrodible character of the alloy has been found to be produced principally by the presence of chromium in the alloy,

' though chromium has also been found to intoughness. resistance. to slip, hardness and other similar characteristics. As a. general rule it'has been found preferable to mainifi; the tungsten content between 7% and The carbon content is preferably maintained in the neighborhood of 0.50%.

A particular alloy which has been found suitable in accordance with the invention tions by weight.

Per cent. Nickel 7. 41 Tungsten" 1 9. 10 Chromiumun; 6. 07 Manganese 3. 95, Carbon 0. 59 Iron 72. 88

It will be appreciated, however, that it is not intended to impose any restrictions upon the proportions of the ingredients employed other than those set forth in the claims.

It has also been found that molybdenum may be used to partially or wholly replace the tungsten content in the formation of steel alloys in accordance with this invention. Accordingly, the term tungsten-like metal has been employed herein to denote either the element tungsten or molybdenum, or a combination of the two.

In addition to being non-magnetic, alloys formed in accordance with the invention, have been found to possess especially good mechanical properties, particularly asregards hardness and resistance to abrasion. Tests. for example, on a specimen which was machined from a hot rolled rod and submitted to mechanical tests, gave the following results:

Diameter, 0.2867 in.; area, 0.0645 sq. in; Rockwell hardness C, 34; scleroscope hardness D, maximum load, 9,822 lbs; strength, 152,800 psi; elongation in 2". 0.22 in.; elongation in 2", 11.0%: P-limit, 54,000 psi.; yield point, 95,000 reduction in area, 0.0102; reduction in area, 15.8%.

In addition, tests have indicated that cold working the material results in an increase of the P-limit to between 85,000 and 95,000 psi. The ultimate tensity strength of a cold rolled ribbon produced from alloys in accordance with the invention'was found to be in the neighborhood of 233,000 pounds per square inch.

Annealing cold rolled samples of alloys formed in accordance with the invention, has been found to materially increase the toughness and ductility; tests indicated, for example, that wires produced from these alloys and annealed could be tied in a knot and subjected tostress without rupture. Furthermore, it has been found that annealing wires formed from these alloys, caused substantially no change in the other properties of the alloys.

Alloys may be formed in accordance with the invention from the component elements in any of the ways customary in the arts by incorporating the various elements 1n the molten state, cold rolling or casting, and annealing. The actual heat treatment, that is, as regards temperature of heating and coolmg or quenching, has not been found to substantially alter the properties of the particular alloy produced. Satisfactory alloysm'ay be formed by heating, for example, to 1200 or 1400 C. and subsequently cooling the air,

in the furnace, or quenching in water or.

brine solution. Alloys formed in accordance with these manners have been found to possess substantially the same properties.

7, In addition to being non-magnetic and possessing a high degree of hardness, tough- V ness, resistance to abrasion alloys formed in accordance with the invention have also been found to be particularly resistant to corrosion. Tests have indicated, for example, that the alloy may be placed in a room of high humidity without being substantially affected from the viewpoint of oxidation after a period of three months exposure, whereas ordinary steel under the same conditions was found to be badlyrusted in 48 hours.

These steel alloys have also been found to be easily soldered and tinned, to possess high electrical resistance and to be poor conductors of heat. Further, in a cold work condition, such steels have been found to retain a high degree of resiliency after and during treatment at a red heat. Ingview of this property, such alloys are well adapted for use as springs for holding filaments in vacuum tubes, for example.

Itis'to be understood that small amounts of other metals may be added to the alloy without departing in any way from the invention. For example, traces of other metals added in the form of impurities are not to be weight: Nickel 7 to 20%, tungsten-like metal 7 to 10%, chromium 6 to 8%, manganese 2 to 7%, carbon to iron, remainder.

2. A steel alloy composed of the following metals in substantially the following proportions by weight: Nickel 7 to 9%, tungsten 9%, chromium 6%, manganese 4%, carbon 0.6%, iron remainder.

3. A cable armoring composed of an alloy in accordance with claim 1. 1

In witness whereof, I hereunto subscribe my name this 6th (19. of October A. D. 1925.

I FANCIS F. LUCAS. 

